The present invention concerns a column-type level indicator for tanks or containers of liquids and the like, particularly for oil tanks, provided with means for its outward application.
It is known to make use in industry of column-type indicators, to be applied on the external walls of oil tanks or other containers for liquids so as to measure their level and/or temperature. Indicators of this type consist of a hollow column--of glass or of a transparent polymeric material--fixed to the external wall of the tank and communicating with its inside. Usually, the indicator is fixed to the wall of the tank by making two holes therein for the two screws and nuts emerging from the ends of the indicator column. Said screws, provided with axial and transversal holes, allow the passage of the liquid between the tank and the cavity of said column. The oil--according to the principle of communicating vessels--flowing into the column, reaches a level equal to that of the tank. In this way, the oil level in the tank can be easily measured (possibily, with reference to a scale or to indications in the column); while furthermore, thanks to its direct contact with a thermometer possibly provided therein, one can read also its temperature.
However, the drawback of such indicators lies in the fact that, in order to be fixed to the tank, the nuts for the screws have to be applied and tightened from the inside of the tank, which often involves considerable difficulties from the practical point of view, for example in the case of narrow tanks, or tanks without an easy access.